®
SPX432
1.24V Precision Adjustable Shunt Regulator
FEATURES
■
Low Voltage Operation, 1.24V
■
Trimmed Bandgap to 0.5% and 1%
■
Wide Operating Current, 1mA to 80mA
■
Adjustable Output Voltage, V
REF
to 18V
■
Extended Temp.Range: 0°C to 105°C
■
Low Temperature Coefficient, 50 ppm/°C
■
Offered in TO-92, SOIC, SOT-23-3
■
Replacement for TLV431, AS432
APPLICATIONS
■
Switching Power Supplies
■
Adjustable Supplies
■
Error Amplifiers
Anode
3
SPX432
3 Pin SOT-23
1
Ref
2
Cathode
Now Available in Lead Free Packaging
Refer to page 11 for other pinouts.
■
■
■
■
Single Supply Amplifier
Monitors / VCRs / TVs
Personal Computers
Voltage References
DESCRIPTION
The SPX432 is a 3-terminal adjustable shunt voltage regulator providing a highly accurate 1.24V
bandgap reference with 0.5% tolerance. The SPX432’s thermal stability, wide operating current
(80mA) and temperature range (0°C to 105°C) makes it suitable for a variety of applications. SPX432
tolerance of 0.5% is proven to be sufficient to overcome all of the other errors in the system to virtually
eliminate the need for trimming in the power supply manufactures’ assembly lines and contribute a
significant cost savings.
The SPX432 is an ideal voltage reference in an isolated feedback circuit for switch mode power
supplies. SPX432 offers many advantages over the TLV431 such as wider output voltage (18V vs.
6V), higher output current (80mA vs. 15mA) and a wider operating temperature range with a tighter
tolerance down to 0.5%.
BLOCK DIAGRAM
Cathode (K)
Reference
(R)
+
-
1.24V
Anode (A)
Date: 12/11/04
SPX432 1.24V Precision Adjustable Shunt Regulator
© Copyright 2004 Sipex Corporation
1
ABSOLUTE MAXIMUM RATINGS
Cathode-Anode Reverse Breakdown V
KA
....................................... 20V
Anode-Cathode Forward Current, (<10ms) I
AK
................................. 1A
Operating Cathode Current I
KA
.................................................... 80mA
Reference Input Current I
REF
.......................................................... 1mA
Continuous Power Dissipation at 25°C P
D
TO-92 ..................................................................... 775mW
SOT-23 .................................................................. 200 mW
SOIC-8 .................................................................... 750mW
Junction Temperature T
J
........................................................... 150
°C
Storage Temperature T
STG
.......................................... -65°C to 150
°C
Lead Temperature (Soldering 10 sec.) T
L
.................................. 300°C
Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. This is a stress rating only
and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not
implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
RECOMMENDED CONDITIONS
PARAMETER
Cathode Voltage
Cathode Current
SYMBOL
V
KA
I
K
RATING
V
REF
to 18
10
UNIT
V
mA
TYPICAL THERMAL RESISTANCES
PACKAGE
TO-92
SOT-23
SOIC-8
0
JA
160°C/W
175°C/W
0
JC
80°C/W
45°C/W
TYPICAL
DERATING
6.3mW/°C
1.7 mW/°C
5.7mW/°C
575°C/W 150°C/W
Typical deratings of the thermal resistances are given for ambient
temperature >25°C.
ELECTRICAL CHARACTERISTICS
Electrical characteristics are guaranted over the full junction temperature range (0°C to 105°C). Ambient temperature must
be derated based upon power dissipation and package thermal characteristics. Unless otherwise specified, test conditions are:
V
KA
= V
REF
and I
K
= 10mA.
PARAMETER
SYMBOL
TEST
CIRCUIT
SPX432A
Output Voltage
Temperature Deviation
Line Regulation
Load Regulation
Reference Input Current
Reference Input Current
Temperature Coefficient
Minimim Cathode
Current for Regulation
Off State Leakage
V
REF
V
REF
V
REF
V
REF
I
REF
I
REF
I
K(MIN)
I
K(MIN)
3a
3a
3b
3a
3b
3b
3a
3c
V
REF
= 0V,
V
KA
= 18V
0 < T
J
< 105°C,
0 < T
J
< 105°C
V
KA
= 1.25V to 15V
I
K
= 1mA to 80mA
1.2338
1.240
12
19
12
3
0.3
0.6
0.04
1.2462
20
37
30
6
0.6
1
500
1.2276
SPX432
1.240
12
19
12
3
0.3
0.6
0.04
1.2524
20
37
30
6
0.6
1
500
V
mV
mV
mV
µA
µA
mA
nA
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
Date: 12/11/04
SPX432 1.24V Precision Adjustable Shunt Regulator
© Copyright 2004 Sipex Corporation
2
CALCULATION AVERAGE TEMPERATURE COEFICIENT (TC)
ppm
0
%
0
mV
0
∆V
REF
∆T
-5
•
TC in mV /
°C
=
∆
V
REF
(mV)
∆
T
A
•
TC in % /
°C
=
(
∆
V
REF
∆
V
REF
at 25°C
∆
T
A
)
x 100
5000
0.5
0
15
30
45
60
75
90
105
•
TC in ppm /
°C
=
(
∆
V
REF
∆
V
REF
at 25°C
∆
T
A
)
x 10
6
Junction Temperature (°C)
0.0033mV /°C
0.0027% /
°C
27ppm/°C
Figure 1. V
REF
VS Temperature.
TEST CIRCUITS
V
IN
V
KA =
V
REF
V
IN
V
KA
V
IN
V
KA
I
K (OFF)
I
REF
I
K
R1
I
REF
(V
REF
)
R2
I
K
Figure 2. Test Circuit for V
KA
= V
REF
Figure 3. Test Circuit for V
KA
> V
REF
Figure 4. Test Circuit for I
KOFF
Date: 12/11/04
SPX432 1.24V Precision Adjustable Shunt Regulator
© Copyright 2004 Sipex Corporation
3
TYPICAL PERFORMANCE CHARACTERISTICS
15.0
12.5
10.0
I
K
Cathode Current (mA)
V
KA
= V
REF
0°C to 105°C
900
800
700
600
=
V
KA
= V
REF
Temperature Range: 0°C to 105°C
5.0
2.5
0
-2.5
-5.0
-7.5
-10.0
-2
-1
0
1
2
V
KA
Cathode Voltage (V)
3
I
K
- Cathode Current (µA)
7.5
500
400
105 °C
300
25 °C
200
-0 °C
100
0
-100
-200
-1.0
-0.5
0
0.25
0.5
0.75
1.0
1.25
1.5
1.24
V
KA
- Cathode Voltage (V)
High Current Operating Characteristics.
Low Current Operating Characteristics.
V
REF
-Reference Voltage (V)
1.245
1.24
1.235
1.23
1.225
1.22
-60
-30
0
30
60
90
120
T
A
-Ambient Temperature (C)
I
REF
-Reference Input Current
(uA)
1.25
3
2.5
2
1.5
1
0.5
0
-60
-30
0
30
60
90
T
A
-Ambient Temperature (C)
V
KA
= V
REF,
I
KA
= 10mA.
Reference Input Current VS Temperature; I
KA
= 10mA.
1.25
V
KA
--Cathode Voltage (V)
0
-10
1.245
dV
REF
(mV)
-20
-30
-40
-50
1.24
1.235
0.01
0.1
1
I
K
--cathode Current (mA)
10
100
0
3
6
9
12
15
18
21
V
KA
-Cathode Voltage (V)
V
KA
= V
REF,
Sweeping I
KA
, 25°C.
Reference Voltage Line Regulation; I
KA
= 10mA
,
Sweeping V
KA
, 25°C.
Date: 12/11/04
SPX432 1.24V Precision Adjustable Shunt Regulator
© Copyright 2004 Sipex Corporation
4
TYPICAL PERFORMANCE CHARACTERISTICS
1000.0000
100.0000
70
Noise Voltage nV/√Hz
60
50
40
30
20
10
0
10
V
KA
= V
REF
I
K
= 10mA
T
A
= 25°C
100
1K
10K
100K
I
KOFF
Cathode Current (nA)
10.0000
1.0000
0.1000
0.0100
0.0010
0.0001
-50
0
50
100
150
T
A
Ambient Temperature (C)
f Frequency (Hz)
Off State Leakage; V
KA
= 18V, V
REF
= 0V.
Noise Voltage VS Frequency.
100
0.150
Z
KA
Dynamic Impedance (Ω)
0.125
0.100
0.075
0.050
0.025
0.0
-60
Z
KA
- Dynamic Impedance (Ω)
V
KA
= V
REF
I
K
= 1 to 80mA
f≤1kHz
T
A
= 25
°C
I
K
= 1 to 80 mA
10
1.0
0.1
0.01
1k
10 k
100 k
1M
10 M
-30
0
30
60
90
120
T
A
Free Air Temperature
f - Frequency (Hz)
Low Frequency Dinamic Output Impedance VS T
AMBIENT
.
Dynamic Output Impedance T
A
= 25°C, I
KA
= 1 to 80mA.
REF LEVEL
0.0deg
70.000dB
70dB
60dB
/DIV
45.000deg
10.000dB
MARKER 735
PHASE (A/R)
MARKER 735
MAG (A/R)
074.781Hz
87.012deg
074.781Hz
0.047dB
215°
180°
PHASE
135°
V
OUT
I
K
230
Ω
50dB
40dB
30dB
20dB
10dB
0dB
GAIN
-10dB
-20dB
-30dB
10
15kΩ
90°
10
µF
45°
0°
-45°
-90°
V
IN
3.03kΩ
GND
-135°
-180°
-215°
10M
100
1K
10K
100K
1M
START 10.000Hz
STOP 10 000 000.000Hz
Small Signal Gain and Phase VS Frequency; I
K
= 10mA,
T
A
= 25°C.
Test Circuit for Gain and Phase Frequency Response.
Date: 12/11/04
SPX432 1.24V Precision Adjustable Shunt Regulator
© Copyright 2004 Sipex Corporation
5